This invention relates to performing geoscience interpretation with simulated data.
Geologists, geophysicists, petroleum engineers and production engineers use models, including computerized models, of the earth's shell to plan exploration and production of hydrocarbons and, to a lesser extent, other minerals. As hydrocarbons become more and more scarce, the accuracy of the computerized models becomes increasingly important to limiting the cost of locating and producing hydrocarbons and the associated cost of hydrocarbon products, such as gasoline and heating oil.
Existing modeling systems use an "inversion" technique to model geoscience structures from acquired data. Acquired data, such as velocity measurements or data collected through seismic instrumentation, is "inverted" and used to predict the location of subsurface structures and the physical properties of those subsurface structures.
Once the inversion process produces predictions of the locations and physical properties of the subsurface structures, they are modeled geometrically. Such models must be capable of representing complicated geometrical shapes, such as the shape of a salt dome or salt wall or the shape of a group of folded sedimentary beds.
Commonly, modeling systems use a grid system to represent subsurface structures. In a grid system, the subsurface structures are represented by points in space regularly spaced in the x-y plane and having a single value in the z plane. The values corresponding to those subsurface structures between the regularly-spaced points are determined by interpolation. In a model for a large subsurface region, the number of points in space can be numerous, requiring a great deal of storage, even if the subsurface structures are uniform in topography and physical properties across that space.
Another modeling system that has been applied to the problem of modeling subsurface structures is constructional solid geometry ("CSG"). Under this approach, two or more solid primitives (such as cylinders or spheres) are combined to form a more complicated solid. The process begins with objects that are known to be solid and adds or subtracts other solids to create new shapes. For example, subtracting a cylinder from a box will produce a box with a hole in it.